Teas, both green and black teas, contain caffeine, but the caffeine in these drinks does not appear to be as physiologically available as in coffee. In fact, green tea is believed to have a relaxing benefit owing to the flavanols (i.e., the catechins and epicatechins) present in green tea.
Green tea has had several physiological benefits attributed to it. It is believed to lower blood pressure and to have other soothing and healing benefits. It is believed that the flavanols are responsible for these benefits. These flavanols readily polymerize when green tea is converted to black tea; therefore, black tea contains very low amounts of catechins, epicatechin and their derivatives.
Black tea is considered to be a stimulating beverage. This is probably due to its higher levels of caffeine in relation to the unpolymerized flavanols.
The effect of mixtures of these catechins and epicatechin with caffeine on the stimulatory effect of caffeine has been shown in French patent No. 2,586,532 issued to Glenshard, et al (1987) in which an extract of cola was studied. This extract was prepared and studied in a dry state since cola extracts are not stable in a liquid state. Laboratory animals were fed this extract and their activity studied. When caffeine and catechin or epicatechin mixtures were fed to the animals, caffeine was said to have a delayed reaction time, i.e. activity of the animals was slower to start than when caffeine alone was fed to the animals. The stimulating effect of caffeine was also more controlled and longer lasting when caffeine was administered in the form of this cola extract. Ratios of caffeine to catechins in the range of 8:1 to 1:2.5 are disclosed. The cola extract had to be administered and kept in a dry state. This is a disadvantage of the cola extract.
Another way to control the stimulatory effect of caffeine and related methylxanthines has been through the use of pyridines and related pyridine compounds. The preferred beverages for the addition of these pyridines are tea, coffee, cocoa, and colas. See for example UK patent No. 1,510,583 (1978) and U.S. Pat. No. 4,076,856 (1978).
While the beneficial effects of green tea solids and of the flavanols are suggested by the literature, the use of these materials in beverages other than green tea or cola and the specific combination of these catechins with caffeine in a stable form in beverages is not known.
Therefore, it is an object of this invention to provide a beverage, which provides the beneficial effects of flavanols and which is stable in liquid form.
It is another object of this invention to provide a beverage which contains caffeine and which provides the alertness benefit of caffeine along with the beneficial effects of the flavanols or green tea solids.
These and other objects will become apparent from the description herein.
All percentages are by weight unless otherwise indicated.